Skull Shape and Size Diversification in the Genus Ctenomys (Rodentia: Ctenomyidae)

Tuco-Tucos ◽  
2021 ◽  
pp. 113-140
Author(s):  
Rodrigo Fornel ◽  
Renan Maestri ◽  
Pedro Cordeiro-Estrela ◽  
Thales Renato Ochotorena de Freitas
Keyword(s):  
Skull Shape ◽  
Shape And Size

scholarly journals SKULL SHAPE AND SIZE DIVERGENCE IN DOLPHINS OF THE GENUS SOTALIA: A TRIDIMENSIONAL MORPHOMETRIC ANALYSIS

2002 ◽  
Vol 83 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Emygdio Leite de Araujo Monteiro-Filho ◽  
Leandro Rabello Monteiro ◽  
Sérgio Furtado dos Reis
Keyword(s):  
Morphometric Analysis ◽  
Skull Shape ◽  
Shape And Size

scholarly journals Beyond the carapace: skull shape variation and morphological systematics of long-nosed armadillos (genus Dasypus)

2017 ◽  
Author(s):  
Lionel Hautier ◽  
Guillaume Billet ◽  
Benoit De Thoisy ◽  
Frédéric Delsuc
Keyword(s):  
Morphological Variation ◽  
Distinct Species ◽  
Morphological Characters ◽  
Molecular Data ◽  
Guiana Shield ◽  
Shape Variation ◽  
Skull Morphology ◽  
Geometric Morphometric ◽  
Skull Shape ◽  
Shape And Size

Background. The systematics of long-nosed armadillos (genus Dasypus) has been mainly based on a handful of external morphological characters and classical measurements. Here, we studied the pattern of morphological variation in the skull of long-nosed armadillos species, with a focus on the systematics of the widely distributed nine-banded armadillo (D. novemcinctus). Methods. We present the first exhaustive 3D comparison of the skull morphology within the genus Dasypus, based on µCT-scans. We used geometric morphometric approaches to explore the patterns of the intra- and interspecific morphological variation of the skull with regard to several factors such as taxonomy, geography, allometry, and sexual dimorphism. Results. We show that the shape and size of the skull vary greatly between Dasypus species, with D. pilosus representing a clear outlier compared to other long-nosed armadillos. The study of the cranial intraspecific variation in D. novemcinctus evidences clear links to the geographic distribution and argue in favour of a revision of past taxonomic delimitations. Our detailed morphometric comparisons detected previously overlooked morphotypes of nine-banded armadillo, especially a very distinctive unit circumscribed to the Guiana Shield. Discussion. As our results are congruent with recent molecular data and analyses of the structure of paranasal sinuses, we propose that D. novemcinctus should be regarded either as a polytypic species (with three to four subspecies) or as a complex of several distinct species.

Skull Shape and Size Divergence in Dolphins of the Genus Sotalia: A Tridimensional Morphometric Analysis

2002 ◽  
Vol 83 (1) ◽  
pp. 125-134 ◽  
Author(s):  
E. L. De Araujo Monteiro-Filho ◽  
L. R. Monteiro ◽  
S. F. Dos Reis
Keyword(s):  
Morphometric Analysis ◽  
Skull Shape ◽  
Shape And Size

Geographic variation in skull shape and size of the Pampas fox Lycalopex gymnocercus (Carnivora: Canidae) in Argentina

2019 ◽  
Vol 97 ◽  
pp. 50-58 ◽  
Author(s):  
Mauro Ignacio Schiaffini ◽  
Valentina Segura ◽  
Francisco Juan Prevosti
Keyword(s):  
Geographic Variation ◽  
Skull Shape ◽  
Shape And Size

scholarly journals Beyond the carapace: skull shape variation and morphological systematics of long-nosed armadillos (genus Dasypus)

2017 ◽  
Author(s):  
Lionel Hautier ◽  
Guillaume Billet ◽  
Benoit De Thoisy ◽  
Frédéric Delsuc
Keyword(s):  
Morphological Variation ◽  
Distinct Species ◽  
Morphological Characters ◽  
Molecular Data ◽  
Guiana Shield ◽  
Shape Variation ◽  
Skull Morphology ◽  
Geometric Morphometric ◽  
Skull Shape ◽  
Shape And Size

Background. The systematics of long-nosed armadillos (genus Dasypus) has been mainly based on a handful of external morphological characters and classical measurements. Here, we studied the pattern of morphological variation in the skull of long-nosed armadillos species, with a focus on the systematics of the widely distributed nine-banded armadillo (D. novemcinctus). Methods. We present the first exhaustive 3D comparison of the skull morphology within the genus Dasypus, based on µCT-scans. We used geometric morphometric approaches to explore the patterns of the intra- and interspecific morphological variation of the skull with regard to several factors such as taxonomy, geography, allometry, and sexual dimorphism. Results. We show that the shape and size of the skull vary greatly between Dasypus species, with D. pilosus representing a clear outlier compared to other long-nosed armadillos. The study of the cranial intraspecific variation in D. novemcinctus evidences clear links to the geographic distribution and argue in favour of a revision of past taxonomic delimitations. Our detailed morphometric comparisons detected previously overlooked morphotypes of nine-banded armadillo, especially a very distinctive unit circumscribed to the Guiana Shield. Discussion. As our results are congruent with recent molecular data and analyses of the structure of paranasal sinuses, we propose that D. novemcinctus should be regarded either as a polytypic species (with three to four subspecies) or as a complex of several distinct species.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

ULTRA-FORM 80

Alloy Digest ◽  
1973 ◽  
Vol 22 (7) ◽  
Keyword(s):  
High Strength ◽  
Heat Treating ◽  
Low Carbon ◽  
Low Alloy Steel ◽  
Bethlehem Steel Corporation ◽  
Temperature Performance ◽  
Inclusion Shape ◽  
Ferrite Grain Size ◽  
Minimum Yield ◽  
Shape And Size

Abstract Ultra-Form 80 is a low-alloy steel developed for its combination of high strength, good formability, fatigue resistance, toughness and weldability. It has a minimum yield strength of 80,000 psi and is characterized by its low carbon and alloy content, very fine ferrite grain size, and controlled inclusion shape and size. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, joining, and surface treatment. Filing Code: SA-291. Producer or source: Bethlehem Steel Corporation.

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